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161.
Influence of ion-molecular reactions on μ-capture in hydrogen and on fusion in 3Hedμ muonic molecule
The de-excitation processes (J=1)→ (J=0) in muonic molecular ions (ppμ)+ and (3Hedμ)+ are studied. It is shown that the rate of such transitions substantially depends on the chain of ion-molecular reactions
initiated by positively charged muonic ions.
The probabilities of ortho-para transition in the [(ppμ)+H2] and [(ppμ)+e] complexes formed as a result of chemical reactions in the pure hydrogen were estimated.
Taking into account the ion-molecular processes in D2 + He mixtures, the evaluation of the observed rate λf of nuclear fusion in the 3Hedμ muonic molecules was performed. The expected yield of fusion reactions per muon at the mixture density φ=0.1 and concentration
C
He
=0.05 was obtained to be equal to
.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
162.
T. Matsuo T. Maekawa A. Inaba O. Yamamuro M. Ohama M. Ichikawa T. Tsuchida 《Journal of Molecular Structure》2006,790(1-3):129
The heat capacities of HCrO2 and DCrO2 have been measured at temperatures between 5 and 360 K. A lambda anomaly occurred at 320 K for DCrO2 but not for HCrO2. Infrared spectra were recorded at temperatures between 5 and 405 K. The spectrum of DCrO2 changed at 320 K with respect to the peak wave-number and splitting of some of the vibrations, while those of HCrO2 depended smoothly on temperature. These experimental results are discussed in terms of a deuteration-induced phase transition. 相似文献
163.
ZHENG Jianping LU Fengxiang YU Chunmei & TANG HuayunFaculty of Earth Sciences China University of Geosciences Wuhan China 《科学通报(英文版)》2004,49(3):277-285
Backscattered electron images, in situ Hf isotopes, U-Pb ages and trace elements of zircons in a banded granulite xenolith from Hannuoba basalt have been studied. The results show that the banded granulite is a sample derived from the early lower crust of the North China craton. It is difficult to explain the petrogenesis of the xenolith with a single process. Abundant information on several processes, however, is contained in the granulite. These processes in-clude the addition of mantle material, crustal remelting, metamorphic differentiation and the delamination of early lower crust. About 80% of zircons studied yield ages of 1842 ±40 Ma, except few ages of 3097-2824 Ma and 2489-2447 Ma. The zircons with ages older than 2447 Ma have high εHf (up to +18.3) and high Hf model age (2.5-2.6 Ga), indicating that the primitive materials of the granulite were derived mainly from a depleted mantle source in late Archean. Most εhf of the zircons with early Proterozoic U-Pb age vary around zero, but two have 相似文献
164.
165.
Ivanov E. V. Ivanova N. G. Abrosimov V. K. Lebedeva E. Yu. 《Russian Chemical Bulletin》2001,50(12):2360-2365
The solubility of gaseous krypton in CO(NH2)2—CH3OH (CD3OH) and CO(ND2)2—CH3OD solutions with carbamide concentrations of up to 1.5 solvomolality units (0.026 mole fractions) was measured at 278, 288, 298, 308, and 318 K and at a partial gas pressure of 101325 Pa. The thermodynamic functions of dissolution (solvation) of krypton and the standard Setchenov coefficients were calculated. The solvation of Kr molecules increases upon deuterium substitution and with an increase in the temperature and carbamide concentration. In these solutions, specific contacts between the carbamide and methanol molecules play the predominant role. 相似文献
166.
P. Cacciani J. Cosléou F. Herlemont M. Khelkhal J. Legrand 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(2):199-207
When a gas sample of 13CH3F is prepared with a population of isomers (ortho and para forms) far from the equilibrium given by nuclear spin statistics,
it relaxes towards this equilibrium with an exponential decay rate. This phenomenon called nuclear spin conversion is mainly
governed by intramolecular spin-spin and spin-rotation interactions. In the quantum relaxation model [P.L. Chapovsky, Phys.
Rev. A 43, 3624 (1991)], two pairs of ortho-para levels (J
= 9, K
= 3; J'
= 11, K'
= 1) and (J
= 20, K
= 3; J'
= 21, K'
= 1) are principally responsible for the conversion. The levels of the second pair are coupled by both spin-spin and spin-rotation
interactions. The application of an electric field (up to 10 kV/cm) induces a crossing of the Stark components of this pair,
which is observed for the first time. A specific experimental set-up based on an electric field of alternating triangular
shape is used, which allows the determination of the strength of both interactions via the measurement of the spin conversion decay rates. This work yields the first experimental value for the electronic contribution
to the spin-rotation interaction in 13CH3F.
Received 23 May 2002 / Received in final form 18 September 2002 Published online 21 January 2003
RID="a"
ID="a"e-mail: Patrice.Cacciani@univ-lille1.fr 相似文献
167.
高丰度硅-28同位素的分离技术 总被引:3,自引:1,他引:2
同位素纯硅片具有特殊的物理性质,在信息技术领域有着非常广阔的应用前景。为获得高丰度28Si,利用国产的高速气体离心机,选择SiF4作为分离的工作介质,对硅同位素进行了离心分离实验。通过单机分离实验,调整气体离心机的有关参数,摸索出适合级联分离的单机参数,同时得到气体离心机分离硅同位素的单位质量数的全分离系数γ0。利用由4台离心机组成的级联,经过6个阶段的分离,得到了28Si丰度达到99.5%的样品。实验结果表明,离心法分离硅同位素是完全可行的。 相似文献
168.
Hf isotope composition of zircons and implication for the petrogenesis of Yajiangqiao granite,Hunan Province,China 总被引:8,自引:1,他引:7
WANGXiang W.L.Griffin WANGZhicheng ZHOUXinmin 《科学通报(英文版)》2003,48(10):995-998
In the peralumineous granite of Yajiangqiao zircon population can be divided into two groups (i.e. Zircon Ⅰ and Zircon Ⅱ), which were formed in magmatic chamber and in emplacement place, respectively. The Hf isotope compositions of two stages of zircon show that the host magma was essentially derived from crustal material by melting. However, some higher 176Hf/177Hf ratios indicate that the granitic zircons should contain fine crystal of zircon formed in mantle-derived magma. In fact, the backscattered electron imaging and the electron microprobe analysis reveal that there is another type of zircon included within Zircon Ⅰ, which is quite different from Zircon Ⅰ and Zircon Ⅱ in morphology and chemistry. They are considered to be the product of the mantle-derived magma intruded into the granitic magma chamber at the beginning of anatexis. Thus,it is suggested that the formation of Yajiangqiao granite is related to the underplating of mantle magma. 相似文献
169.
N.A. Babushkina L.M. Belova E.A. Chistotina O.Yu. Gorbenko A.R. Kaul B. Güttler K.I. Kugel 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,19(3):409-415
The effect of
16
O
→
18
O isotope substitution on electrical resistivity, magnetoresistance, and ac magnetic susceptibility was studied for La0.35Pr0.35Ca0.3MnO3 epitaxial thin films deposited onto LaAlO3 and SrTiO3 substrates. For the films on LaAlO3, the isotope substitution resulted in the reversible transition from a metal-like to insulating state. The applied magnetic
field ( H
≥ 2
T) transformed the sample with 18O back to the metallic state. The films on SrTiO3 remained metallic at low temperatures for both 16O and 18O, but the shift of the resistivity peak corresponding to onset of metallic state exceeded 63 K after
16
O
→
18
O substitution. The temperature dependence of both resistivity and magnetic susceptibility was characterized by hysteresis,
especially pronounced in the case of the films on LaAlO3. Such a behavior gives certain indications of the phase separation characteristic of interplay between ferromagnetism and
charge ordering.
Received 11 February 2000 and Received in final form 13 September 2000 相似文献
170.
Discussion of gas enrichment mechanism and natural gas origin in marine sedimentary basin,China 总被引:4,自引:0,他引:4
《科学通报(英文版)》2007,52(Z1)
There are abundant natural gas resources in Chinese marine sedimentary basin. The exploration hot shots of natural gas are the Palaeozoic marine strata here in recent years, and several large scale gas fields have been discovered. Chinese Palaeozoic high-post matured and coal measure hydrocarbon source rocks are mainly prone to gas generation in the present. This research considered that gas source rocks and TSR are the key cause of gas enrichment of marine strata. High-quality argillaceous and coal measure hydrocarbon rocks are distributed widely in the Palaeozoic marine strata, which have been in highly matured phase in the present. The argillaceous source rock generally contains various sulfates that could accelerate crude oil cracking to gas for TSR occurrence, and coal measure source rock mainly generates gas, so Chinese marine basin gives priority to accumulating gas. Marine strata have not founded oil reservoirs in the Sichuan Basin and Ordos Basin, and they consist mainly of dry gas. Marine natural gases are the mixed gases of oil cracking gas and coal-formed gas in a general way, oil cracking gases contain usually some H2S and CO2. Hydrocarbon carbon isotopes are very complicated, and methane and ethane isotopic values bear apparent reversal caused by thermal evolution and mixing among different genetic types of natural gas. Coal-formed gases are the main component of Chinese marine natural gas. The Upper Permian of the Sichuan Basin and the Carboniferous-Permian of the Ordos Basin coal measure hydrocarbon source rock present large hydrocarbon generation potential, which are the prospecting highlight of marine natural gas hereafter. Oil cracking gas exploration will be paid much attention to in the Tarim Basin because of the lack of coal measure hydrocarbon source rock. 相似文献